1. Briggs, K. C. (2014). Blended learning vs. face-to-face instruction: A quantitative evaluation of student achievement in algebra I. Available from ProQuest Dissertations & Theses Full Text: The Humanities and Social Sciences Collection. (1640913684)
2. Brodersen, R. M., & Melluso, D. (2017). Summary of research on online and blended learning programs that offer differentiated learning options (REL 2017–228). Washington, DC: U.S. Department of Education, Institute of Education Sciences, National Center for Education Evaluation and Regional Assistance, Regional Educational Laboratory Central.
http://ies.ed.gov/ncee/edlabs
. Accessed 2 May 2018.
3. Columbia University (n.d.). Difference-in-Difference estimation.
https://www.mailman.columbia.edu/research/population-health-methods/difference-difference-estimation
. Accessed 20 Jan 2019.
4. Education Elements (2015, September 29). The positive power of personalized learning: Education Elements impact 2014–2015.
https://cdn2.hubspot.net/hubfs/428371/Impact_report_2014_-15/EducationElements_ImpactReport_2014-2015.pdf
. Accessed 30 Mar 2019.
5. Fazal, M., & Bryant, M. (2019). Blended learning in middle school math: The question of effectiveness. Journal of Online Learning Research, 5(1), 49–64.